The hormone $Melatonin$ is produced by the:

Melatonin is secreted by the . . . . . . .

The organ which was considered vestigial until recently but is now confirmed to be an endocrine gland is:

Artificial light, extended work-time and reduced sleep-time disrupt the activity of

The pineal body originates from:

$P$ is a small,round,reddish structure located on the dorsal side of the forebrain. It contains a stalk and releases a hormone $Q$ which controls the diurnal rhythm of the body. $P$ and $Q$ are